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dan(at)syz.com
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 Posted: Fri Dec 02, 2016 11:16 pm Post subject: Low max static RPM |
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Hi everyone. I'm wondering if anyone else has experienced what I am.
I'm just about ready for first flight in my RV-10 (inspection's done, paperwork's back.. it's legally an airplane now, so just doing some final tidying up (and waiting for a good weather day).
I have a Lycoming YIO-540-D4A5 with an MTV-12-B prop and Hartzell S-1-32 governor - pretty much stock Van's recommended equipment, and supplied directly by them. During a static engine runup, I only got to a maximum RPM of 2500... and from what I understand, 2650 is closer to what I should be shooting for. So I adjusted the max RPM adjustment screw on the governor and tried again, but there was no change (and the governor arm does touch the high RPM screw on when set to max RPM)
The shop that assembled my MTV-12-B, as well as Hartzell and Van's have all suggested that the low pitch stop may be limiting the static RPM (another suggestion they made was to ensure my tach was reading accurate. I don't have an optical tachometer to check it, though I could buy one if it's worth doing... though since my RPM is monitored through an Advanced Flight Systems sensor that goes on an magneto, it doesn't seem likely to me that there would be a small error... digital as I believe it is, I would suspect it to either work perfectly, or not at all).
In any case, has anyone else run into something like this? A friend of mine with a flying RV-10 has mentioned he does get in the neighbourhood of 2650 on his takeoff roll... though his engine produces closer to 300 HP vs my 260 HP, and he has a different governor than I do as well. My reading also wasn't really on a takeoff roll - I was stationary, and though I tried accelerating a bit, never got up to more than maybe 20 knots before I powered back, so perhaps it will increase a bit once I start moving. Density altitude at the time was around minus 500 feet due to temperatures at about -10 degrees C.
It's a new engine from Lycoming, so I want to run it as little as possible on the ground, giving it a proper breakin while flying. My thoughts are that 2500 RPM should still be more than adequate for takeoff power on a first flight (cold temperatures here, no significant obstacles, light weight in the airplane, etc.) and then I might tweak either the governor more and/or low pitch stops a bit between subsequent flights to see if I can increase my takeoff RPM a bit.
Just wondering - has anybody else run into anything like this, or have any suggestions?
Thanks!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
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jesse(at)saintaviation.co
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| Posted: Sat Dec 03, 2016 5:21 am Post subject: Low max static RPM |
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2500 rpm gives plenty of power for flight, so just fly and see what your max rpm is on takeoff. 2575 rpm makes 250HP, so you'll be fine.
Enjoy!
Jesse Saint
Saint Aviation, Inc.
jesse(at)saintaviation.com
C: 352-427-0285
F: 815-377-3694
Sent from my iPhone
| Quote: | On Dec 3, 2016, at 2:15 AM, Dan Charrois <dan(at)syz.com> wrote:
Hi everyone. I'm wondering if anyone else has experienced what I am.
I'm just about ready for first flight in my RV-10 (inspection's done, paperwork's back.. it's legally an airplane now, so just doing some final tidying up (and waiting for a good weather day).
I have a Lycoming YIO-540-D4A5 with an MTV-12-B prop and Hartzell S-1-32 governor - pretty much stock Van's recommended equipment, and supplied directly by them. During a static engine runup, I only got to a maximum RPM of 2500... and from what I understand, 2650 is closer to what I should be shooting for. So I adjusted the max RPM adjustment screw on the governor and tried again, but there was no change (and the governor arm does touch the high RPM screw on when set to max RPM)
The shop that assembled my MTV-12-B, as well as Hartzell and Van's have all suggested that the low pitch stop may be limiting the static RPM (another suggestion they made was to ensure my tach was reading accurate. I don't have an optical tachometer to check it, though I could buy one if it's worth doing... though since my RPM is monitored through an Advanced Flight Systems sensor that goes on an magneto, it doesn't seem likely to me that there would be a small error... digital as I believe it is, I would suspect it to either work perfectly, or not at all).
In any case, has anyone else run into something like this? A friend of mine with a flying RV-10 has mentioned he does get in the neighbourhood of 2650 on his takeoff roll... though his engine produces closer to 300 HP vs my 260 HP, and he has a different governor than I do as well. My reading also wasn't really on a takeoff roll - I was stationary, and though I tried accelerating a bit, never got up to more than maybe 20 knots before I powered back, so perhaps it will increase a bit once I start moving. Density altitude at the time was around minus 500 feet due to temperatures at about -10 degrees C.
It's a new engine from Lycoming, so I want to run it as little as possible on the ground, giving it a proper breakin while flying. My thoughts are that 2500 RPM should still be more than adequate for takeoff power on a first flight (cold temperatures here, no significant obstacles, light weight in the airplane, etc.) and then I might tweak either the governor more and/or low pitch stops a bit between subsequent flights to see if I can increase my takeoff RPM a bit.
Just wondering - has anybody else run into anything like this, or have any suggestions?
Thanks!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
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Tim Olson
Joined: 25 Jan 2007
Posts: 2871
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| Posted: Sat Dec 03, 2016 5:50 am Post subject: Low max static RPM |
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I would agree. It should fly fine. Don't try to do too much with it on the ground just yet until you see how it is in flight. But, once you get it flyIng, you should have many opportunities for in cowling it and adjusting things. Then you can tweak it without worrying about hurting your fresh engine.
Tim
| Quote: | On Dec 3, 2016, at 7:21 AM, Jesse Saint <jesse(at)saintaviation.com> wrote:
2500 rpm gives plenty of power for flight, so just fly and see what your max rpm is on takeoff. 2575 rpm makes 250HP, so you'll be fine.
Enjoy!
Jesse Saint
Saint Aviation, Inc.
jesse(at)saintaviation.com
C: 352-427-0285
F: 815-377-3694
Sent from my iPhone
> On Dec 3, 2016, at 2:15 AM, Dan Charrois <dan(at)syz.com> wrote:
>
>
>
> Hi everyone. I'm wondering if anyone else has experienced what I am.
>
> I'm just about ready for first flight in my RV-10 (inspection's done, paperwork's back.. it's legally an airplane now, so just doing some final tidying up (and waiting for a good weather day).
>
> I have a Lycoming YIO-540-D4A5 with an MTV-12-B prop and Hartzell S-1-32 governor - pretty much stock Van's recommended equipment, and supplied directly by them. During a static engine runup, I only got to a maximum RPM of 2500... and from what I understand, 2650 is closer to what I should be shooting for. So I adjusted the max RPM adjustment screw on the governor and tried again, but there was no change (and the governor arm does touch the high RPM screw on when set to max RPM)
>
> The shop that assembled my MTV-12-B, as well as Hartzell and Van's have all suggested that the low pitch stop may be limiting the static RPM (another suggestion they made was to ensure my tach was reading accurate. I don't have an optical tachometer to check it, though I could buy one if it's worth doing... though since my RPM is monitored through an Advanced Flight Systems sensor that goes on an magneto, it doesn't seem likely to me that there would be a small error... digital as I believe it is, I would suspect it to either work perfectly, or not at all).
>
> In any case, has anyone else run into something like this? A friend of mine with a flying RV-10 has mentioned he does get in the neighbourhood of 2650 on his takeoff roll... though his engine produces closer to 300 HP vs my 260 HP, and he has a different governor than I do as well. My reading also wasn't really on a takeoff roll - I was stationary, and though I tried accelerating a bit, never got up to more than maybe 20 knots before I powered back, so perhaps it will increase a bit once I start moving. Density altitude at the time was around minus 500 feet due to temperatures at about -10 degrees C.
>
> It's a new engine from Lycoming, so I want to run it as little as possible on the ground, giving it a proper breakin while flying. My thoughts are that 2500 RPM should still be more than adequate for takeoff power on a first flight (cold temperatures here, no significant obstacles, light weight in the airplane, etc.) and then I might tweak either the governor more and/or low pitch stops a bit between subsequent flights to see if I can increase my takeoff RPM a bit.
>
> Just wondering - has anybody else run into anything like this, or have any suggestions?
>
> Thanks!
>
> Dan
> ---
> Dan Charrois
> President, Syzygy Research & Technology
> Phone: 780-961-2213
>
>
>
>
>
|
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
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Kelly McMullen
Joined: 16 Apr 2008
Posts: 1188
Location: Sun Lakes AZ
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| Posted: Sat Dec 03, 2016 6:17 am Post subject: Low max static RPM |
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Right now I would not concern yourself too much about static rpm. A stock IO-540 in certified condition, i.e. stock compression of 8.5 to 1 is rated at 250 hp at 2575 rpm (as installed in the Piper Aztec). My main concern at -10 C would be getting the oil warm enough. I would want at least 100-120 F for take-off on first flight. I would want CHT above about 225 F. At a below sea level DA your engine will make more power, and you will have noticeably more lift. For a solo first flight, or even with the additional pilot program (highly recommended) your initial take off weight will be between 2200 and 2300 lbs. More than enough power at those weights. Even bringing the power up slowly, with flaps at 0 degrees, your plane will want to fly within 1000-1500 ft ground roll and will climb quite rapidly. I don't recommend using flaps 15 for first flight...you will overspeed them, just because you will be behind the airplane a bit on that first takeoff. The engine will be quite happy with 2500-2600 rpm, and you won't need to be concerned about dialing the rpm back until you reach your break-in altitude. For noise and comfort, 3500 MSL with 24" and 2400 works pretty well to get 75% give or take a couple percent. At least with your OAT you won't have CHT or oil temp problems to worry about. Once you have a few hours on the engine, it will rev a little freer and you will be able to see what your prop governor will allow at flying speeds. I have your prop, MT governor (with the SB for flyweight assy applied) and I had to watch to prevent overspeed until I sent the governor in for the SB and had them adjust the governor redline down 30 rpm. I have Dynon Skyview which uses connection through resistors to both P-leads for rpm sensing. Because my first flight was at something above 30 C and all of Phase I was hotter temps, and I was fighting high CHT I did a lot of takeoffs at 85% power, reducing to 65% pretty quickly after reaching pattern altitude. I likely will add some more cooling before next summer.
Kelly
-sent from the I-droid implanted in my forearm
On Sat, Dec 3, 2016 at 12:15 AM, Dan Charrois <dan(at)syz.com (dan(at)syz.com)> wrote:
| Quote: | --> RV10-List message posted by: Dan Charrois <dan(at)syz.com (dan(at)syz.com)>
Hi everyone. I'm wondering if anyone else has experienced what I am.
I'm just about ready for first flight in my RV-10 (inspection's done, paperwork's back.. it's legally an airplane now, so just doing some final tidying up (and waiting for a good weather day).
I have a Lycoming YIO-540-D4A5 with an MTV-12-B prop and Hartzell S-1-32 governor - pretty much stock Van's recommended equipment, and supplied directly by them. During a static engine runup, I only got to a maximum RPM of 2500... and from what I understand, 2650 is closer to what I should be shooting for. So I adjusted the max RPM adjustment screw on the governor and tried again, but there was no change (and the governor arm does touch the high RPM screw on when set to max RPM)
The shop that assembled my MTV-12-B, as well as Hartzell and Van's have all suggested that the low pitch stop may be limiting the static RPM (another suggestion they made was to ensure my tach was reading accurate. I don't have an optical tachometer to check it, though I could buy one if it's worth doing... though since my RPM is monitored through an Advanced Flight Systems sensor that goes on an magneto, it doesn't seem likely to me that there would be a small error... digital as I believe it is, I would suspect it to either work perfectly, or not at all).
In any case, has anyone else run into something like this? A friend of mine with a flying RV-10 has mentioned he does get in the neighbourhood of 2650 on his takeoff roll... though his engine produces closer to 300 HP vs my 260 HP, and he has a different governor than I do as well. My reading also wasn't really on a takeoff roll - I was stationary, and though I tried accelerating a bit, never got up to more than maybe 20 knots before I powered back, so perhaps it will increase a bit once I start moving. Density altitude at the time was around minus 500 feet due to temperatures at about -10 degrees C.
It's a new engine from Lycoming, so I want to run it as little as possible on the ground, giving it a proper breakin while flying. My thoughts are that 2500 RPM should still be more than adequate for takeoff power on a first flight (cold temperatures here, no significant obstacles, light weight in the airplane, etc.) and then I might tweak either the governor more and/or low pitch stops a bit between subsequent flights to see if I can increase my takeoff RPM a bit.
Just wondering - has anybody else run into anything like this, or have any suggestions?
Thanks!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
====================================
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